Field of the Disclosure
The present invention relates to a wafer via solder filling device for filling solder in a via formed in a wafer, more particularly, to a wafer via solder filling device including a pressing unit for pressing and moving a molten solder upward.
Discussion of the Related Art
As electronic devices are getting small-sized recently, semiconductor packages used in electronic devices tend to be small-sized. Especially, a plurality of vias may be formed in a wafer to reduce a volume of wafers disposed in layers. Copper is filled in the via in a process of electroplating and wafers are disposed in 3-dimentional, such that wafers may be electrically connected. A method of filling a molten solder in a via, not copper, is recently introduced.
Specifically, when a molten solder is filling in a via of a wafer in prior art, a method for simply exposing a via to a molten solder or a method of melting a solder electroplated on an internal wall of a via is conventionally used.
In case of using such methods, a molten solder could not be filling in the via completely and a void or crack might occur frequently, which could cause a high error rate of wafers.
Moreover, the wafer having the via formed in only one of upper and lower surfaces is provided or the wafer having the via formed through vertically is provided. However, the same filling process is performed, regardless of the via type formed in the wafer. Accordingly, there is a disadvantage of high quality variation in products.
Accordingly, methods for solving such disadvantages are required.